There are known furniture hinges comprising an arm, to be secured to the side panel of the furniture unit, hinged to a pin internally supporting a cup-shaped element designed to be flush-mounted in the door. Said hinges with a single axis of rotation also comprise a spring-operated mechanism to enable them to reach the completely closed position when they are shifted manually close to said position. In the known technique, the spring-operated mechanism comprises a certain number of parts which interact with each other camwise. For example, there are known spring-operated mechanisms composed of a helical spring which pushes a tappet perpendicularly against a cam integrally secured to the cup or arm. Another type of spring-operated mechanism comprises a cylindrical part integrally secured to one of the two elements of the hinge coaxial to the hinging, which is biased by a leaf spring secured to the other element. The cylindrical surface is provided with a suitably positioned flat faceted area which enables the spring to be released and consequently automatically close the door.
Both types of mechanisms require a relatively expensive preassembling operation to secure the part forming the cam surface to the corresponding hinge element. Alternatively, in order to avoid the preassembling operation, the hinge element can be cast in one piece with the cam, thereby avoid the cost of the preassembling operation. However, this procedure is much more expensive than the conventional procedure of pressing from sheet metal. The useful space for housing the cam and spring inside the hinge is extremely limited. Moreover, the dimensions of the arm and the position of the hinge pin are very often restricted by requirements in terms of size, sturdiness and kinematic movement of the hinge. Consequently, it is difficult to find solutions which are at one and the same time inexpensive and fully satisfactory.